Fault tolerant superpixel constructions

ABSTRACT

A process for coloring substrates, using the application of liquid colorants, in which the assignment of color is done on a pixel-by-pixel basis, and corresponding products. Relatively large areas of a substrate may be given the appearance of being uniformly colored by successively replicating or tiling a group of individually colored pixels comprising a repeating unit (i.e., a superpixel) across the substrate surface. The repeating unit is constructed in such a way that if a colorant application error develops, causing one or more pixels within the repeating unit to be colored incorrectly or incompletely, the overall arrangement of the pixels within the repeating unit will render such error less visually apparent when viewed on the substrate.

[0001] The novel development described herein relates to a process forcoloring substrates, using the application of liquid colorants, in whichthe assignment of color is done on a pixel-by-pixel basis. Specifically,the following describes a process, and the resulting product, wherebyrelatively large areas of a substrate may be given the appearance ofbeing uniformly colored by successively replicating or tiling a group ofindividually colored pixels comprising a repeating unit (i.e., asuperpixel) across the substrate surface. The repeating unit isconstructed in such a way that if a colorant application error develops,causing one or more pixels within the repeating unit to be coloredincorrectly or incompletely, the overall arrangement of the pixelswithin the repeating unit will render such error less visually apparentwhen viewed on the substrate.

[0002] Many techniques have been developed for patterning or coloringsubstrates, notably absorbent substrates, and particularly textilesubstrates. With the development of the electronic computer, suchtechniques have included the use of individually addressable dyeapplicators, under computer control, that are capable of dispensing apre-determined, and in some cases, variable, quantity of a dye or liquidcolorant to a specifically identified area or pixel on a substratesurface. Such techniques have been disclosed in, for example,commonly-assigned U.S. Pat. Nos. 4,116,626, 5,136,520, 5,142,481, and5,208,592, the teachings of which are hereby incorporated by reference.

[0003] In the devices and techniques described in the above-referencedU.S. patents, the pattern is defined in terms of pixels, and individualcolorants, or combinations of colorants, are assigned to each pixel inorder to impart the desired color to that corresponding pixel orpixel-sized area on the substrate. The application of such colorants tospecific pixels is achieved through the use of hundreds of individualdye applicators, mounted along the length of color bars that arepositioned across the path of the moving substrate to be patterned. Eachapplicator in a given color bar is supplied with colorant from the samecolorant reservoir, with different arrays being supplied from differentreservoirs, typically containing different colorants. By generatingapplicator actuation instructions that accommodate the position of theapplicator along the length of the color bar and the position of thecolor bar relative to the position of the target pixel on the movingsubstrate, any available colorant from any color bar may be applied toany pixel within the pattern area on the substrate, as may be requiredby the specific pattern being reproduced.

[0004] It is contemplated that other arrangements or techniques forsystematically applying various colorants to a substrate surface inaccordance with pattern data, such as, for example, having one or moresets of colorant applicators that are moved or indexed across the faceof a relatively stationary or intermittently indexed substrate, may alsoemploy the teachings herein.

[0005] Regardless of the nature or configuration of the patterningdevice, a common problem with the use of such devices involves theoccasional malfunction of one or more of the colorant applicators, aswhen such applicators become clogged, blocked, mis-aligned, or otherwisebecome incapable of reliably and accurately dispensing to each assignedpixel the required quantity of the assigned colorant to that pixel. Ifthe malfunction is intermittent, such as an applicator that occasionallydispenses the incorrect quantity of colorant, the resulting patterningirregularity may be relatively unobtrusive, depending, of course, uponthe nature of the pattern being reproduced, the nature of the substratebeing patterned, and other factors. If the malfunction is persistent,such as an applicator that has become blocked, mis-aligned, or hasceased to function altogether, the resulting patterning irregularity maybe so obtrusive as to cause visually objectionable streaks, bands, orthe like that tend to extend in the direction of primary relative motionbetween the colorant applicator(s) and the substrate, hereinafterreferred to as the “machine direction” (e.g., as indicated by the arrowin FIGS. 1 and 2).

[0006] The result of such malfunctions manifests as linear patterninganomalies known as “streaks” or “bands” and may be somewhat visuallyanalogous to the striations associated with old or worn film orvideotape images. Areas of the substrate in which the pattern requires arelatively uniform solid color or shade to be reproduced on thesubstrate are generally the least tolerant of either type ofmalfunction—such malfunctions result in solid color areas that arenon-uniform, either due to the formation of the streaks and bandsreferred to above, or due to otherwise unintended and visuallyobjectionable pattern irregularities. Accordingly, the uniformappearance of such areas patterned by such patterning devices asdescribed above has been particularly dependent upon the absence ofcolorant applicator malfunctions.

[0007] By use of the teachings herein, substrate pattern areas may begenerated that effectively emulate uniformly colored pattern areas, butthat have dramatically increased tolerance for individual colorantapplicator malfunctions that might otherwise render such pattern areasdistinctly non-uniform and visually objectionable. In accordance withone embodiment of the teachings herein, areas of the substrate that areintended to carry a solid color or shade instead may be patterned withan arrangement of different colored pixels, selected to replicate therequired color on the substrate, that collectively comprise a repeatingunit or superpixel.

[0008] The distribution of such colored pixels within such superpixelare carefully constructed to avoid or minimize the formation of visuallyobtrusive clumps or islands of color within the superpixel, as well asthe unintended alignment of such pixels either within a given superpixelor across several superpixels, particularly in the machine direction. Insingle color areas, the former condition tends to promote a speckled orheathered appearance, which may or may not be desirable, while thelatter condition tends to generate visually apparent twill lines undersome conditions. When such repeating unit or superpixel is tiled orotherwise replicated across the substrate surface and observed at adistance, this patterned area—although generally comprised of a densearrangement of chromatically compatible, but not identically colored,pixels—is capable of serving as an effective visual surrogate for auniformly colored solid shade area on the substrate.

[0009] Advantageously, the resulting pattern area, which may, in somecases, result in a somewhat “heathered” appearance, effectivelydisguises patterning irregularities due to the misapplication ofcolorant by individual, improperly functioning colorant applicators inindividual pixel areas, particularly in cases in which colorantapplicator malfunctions are persistent and result in a systematicpatterning irregularity that is replicated throughout the pattern area.It has also been found that, through use of such “fault-tolerant”superpixels, the resulting pattern area tends to allow contours in thesurface of the substrate, as, for example, would be found in amulti-level carpet substrate, to maintain a desired degree of visualprominence, which the generation of bands, streaks, and the like tendsto obscure.

[0010] In another embodiment of the teachings herein, the pixelscomprising the superpixel may be identically colored, but may be coloredin a manner that involves the use of multiple (and technicallyredundant) colorant applicators to provide an applicator-to-pixelrelationship that can disguise individual improperly functioningcolorant applicators, as will be discussed in further detail below.

[0011] For purposes herein, the following terms shall have the indicatedmeanings, unless the context or explicit language otherwise dictates.

[0012] The term “pixel” shall refer to the smallest area or location ina pattern or on a substrate that can be individually assignable oraddressable with a given color.

[0013] The term “pattern” and its derivative terms shall mean assigningor imparting one or more colors to a substrate surface, and shall referboth to the assignment of colors to specific pixels and to thecorresponding dispensing of liquid colorants on the substrate surface.When used in the sense of a pattern on a substrate surface, the termshall refer to the arrangement of textile fibers that have been dyed bythe application, on a pixel-by-pixel basis, of a liquid colorant to thesurface of the substrate. While a pattern typically involves differentcolors, arranged in pre-determined configurations, placed or to beplaced in various areas of the substrate surface, it may also refer tothe assignment or generation of a single color in all areas of thesubstrate surface, i.e., a “solid color” pattern. In either case, thecolor(s) may be generated on the substrate surface through thepixel-by-pixel application of a single liquid colorant (e.g., if thedesired color can be reproduced using a single process color), or theapplication of several different liquid colorants to form an in situblend on the substrate surface.

[0014] The term “heather” and its derivative terms shall mean smallscale chromatic non-uniformities within a patterned area on a substrate,somewhat analogous to grain in a photograph or the halftone structure ina printed halftone image. Substrates with significant heather appearspeckled or stippled when viewed at close range, although may appear toexhibit a solid color when viewed at a greater-viewing distance. In somecases, the generation of heather is desirable, as it provides for thepresentation of a variety of different colors, or different shades ofthe same color, in a way that is visually apparent, but subtle andunobtrusive.

[0015] The term “adjacent” and its derivative terms shall be used tomean contiguous, including along a diagonal, i.e., having a shared,common boundary element, including a common side or a common corner.

[0016] The term “side-wise adjacent” shall refer to a particular kind ofadjacent or contiguous orientation in which the common boundary elementconsists of at least one common side (i.e., the sharing only of a commoncorner falls within the definition of adjacent, but does not fall withinthe definition of side-wise adjacent).

[0017] The term “dithering” shall refer to a computer-generatedreconstruction of an image, using only pixels having colors found in apre-defined “dither palette”. Dithering software generates, inpixel-wise fashion, an image in which each pixel is assigned a colorfrom the dither palette that, when the image is viewed from a distance,best approximates the target color at that location within the pattern.

[0018] The term “Multi-pixel Offset Unit” or “M.O.U.” shall be used todescribe the smallest group of pixels that collectively represent thedesired color. In one embodiment of the teachings herein, an M.O.U. canbe thought of as the major component or building block of a superpixelthat imparts the correct color (but not necessarily the correct internalplacement of pixels) to that superpixel. In that embodiment, severalM.O.U.s are arranged so that pixels having the same color are assignedto different columns (i.e., a series of contiguous pixels extending inthe machine direction) on the substrate. A specific arrangement ofadjacent M.O.U.s can form a superpixel that, when tiled across an areaof the substrate, will form the desired color while minimizing thealignment, in the machine direction, of pixels having the same color,thereby making relatively inconspicuous any patterning irregularities(e.g., the formation of streaks and bands) due to the malfunction of anyspecific colorant applicator.

[0019] The term “superpixel” refers to a pre-defined arrangement ofpixels, each carrying a pre-determined color (generated by a singleprocess colorant, or by an in situ blend of two or more processcolorants applied to the same or adjacent pixels), to be tiled orotherwise replicated across an area on a substrate surface in order toimpart a specified color or pattern effect to that substrate surfacearea. In one embodiment of the teachings herein, a superpixel may beformed by an arrangement of several M.O.U.s or, in another embodiment ofthe teachings herein, may simply be an arrangement of individual pixels.When used in the context of patterning, the terms “superpixel” and“repeating unit” may be used interchangeably. Superpixels can containseveral or dozens of individual pixels.

[0020] The term “machine direction” shall refer to the relativedirection of movement of the colorant applicators as they are dispensingcolorant onto the substrate. It is presumed that the substrate to bepatterned is either in the form of a continuous web, e.g., a broadloomfloor covering, or is in the form of a series of discrete substrateunits, e.g., individual carpet tiles or area rugs, moving along a pathleading through the patterning device of choice. Where the applicatorsare maintained in a fixed position (e.g., on non-moving color bars), themachine direction corresponds to the direction of motion of thesubstrate through the patterning device. Where the applicators aremounted on a moving platform, e.g., one that traverses across the pathof the substrate, the machine direction may be transverse to thedirection of motion of the substrate.

[0021] The terms “column” and “row” shall refer, respectively, to axeswithin pixel arrays extending in the machine direction (column) andtransverse to the machine direction (row), respectively. With respect tothe patterning device of FIGS. 1 and 2, a column of pixels within anM.O.U. or superpixel extends along the length of the conveyor (andextends vertically in the Figures representing individual pixels).

[0022] The term “tile” and its derivative terms shall have theconventional mathematical definition, i.e., to position similarly-shapedelements (such as superpixels or other pattern repeat units) havingcomplementary boundaries in adjacent relationship with one another on asurface, so as to cause said complementary boundaries to become commonboundaries between adjacent elements, and thereby form a continuous,uninterrupted expanse of said elements over the surface on which saidelements are positioned, similar to a jig saw puzzle withidentically-shaped pieces.

[0023] The term “process colorant” and its derivative terms shall referto the colorant applied to the substrate by the colorant applicatorsystem. The term “process color” and its derivative terms shall refer tothe intrinsic color of the process colorant, prior to any mixing withother colorants on the substrate surface. Process colors, therefore, arecolors obtainable without the need for mixing or blending differentcolorants on the substrate.

[0024] The term “twill line” shall refer to the relative position ofsimilarly-colored pixels or pattern elements within a pattern repeatunit that, when the repeat unit is tiled across the substrate, producesan unintended alignment of such pixels or pattern elements that appearsas a visually apparent line or band extending, commonly (but notnecessarily) in a diagonal direction, over multiple superpixels orpattern repeats.

[0025] The term “in situ blend” and its derivative terms shall refer tothe separate application of two or more colorants to the same oradjacent pixels on a substrate, with at least some mixing or blending ofthe colorants taking place following such application.

[0026] The term “target color” shall refer to the color specified in thepattern that is to be reproduced or emulated on the substrate usingprocess colorants, perhaps through the use of in situ blendingtechniques, dithering techniques, or a combination of those techniques.

[0027] The term “fill color” shall refer either to a solid color orshade (i.e., a color or shade that is visually uniform and homogeneous)that is formed by a collection of pixels in which all individual pixelshave been assigned the same color, or to a color that is formed by acollection of pixels in which at least two pixels within the collectionhave been assigned different colors in a manner that minimizes anyvisually discernable pattern to the positioning of differently coloredpixels. In this latter case, the resulting color may exhibit a heatheror stipple effect when viewed at close range, but may give theappearance of a solid color when viewed at a distance.

[0028] The term “fill area” shall refer to areas within a pattern towhich are assigned fill colors.

[0029] The term “periodic” and its derivative terms shall refer to thesystematic, predictable appearance of an irregularity, a specificallycolored pixel, or other identifiable pattern component on the substrate.The term “non-periodic” and its derivative terms shall refer to therandom or quasi-random appearance of such pattern components on thesubstrate.

[0030] The term “pattern artifact” and its derivative terms shall referto the introduction of an unintended design element in situationswherein a repeating unit is replicated within an area of the substrate.A pattern artifact arises when certain components within that repeatingunit become geometrically aligned with similar components in adjacentrepeating units in a way that introduces an unintended design element,such as a twill line, which typically spans many repeating units and isrelatively unobtrusive or non-existent when viewed only within thesingle repeating unit.

[0031] The term “pattern irregularity” and its derivative terms shallrefer to deviations between the pre-determined pattern and the patternas reproduced on the substrate. A pattern irregularity, if periodic, canform a pattern artifact.

[0032] The term “textile floor covering” shall refer to any absorbenttextile substrate (e.g., one that may be described as a non-woven,woven, tufted, bonded, knitted, flocked, or needlepunched textilesubstrate) that is adapted (perhaps with the addition of an appropriatetextile or non-textile backing material) or suitable for placement on afloor or other walking surface. Specifically included as non-limitingexamples are carpets, carpet tiles, broadloom rugs, area rugs and mats,any of which may be variously comprised of polyamide fibers, woolfibers, or combinations thereof. Non-limiting examples of carpet tilesare described in more detail in commonly-assigned U.S. Pat. Nos.4,522,857 and 6,203,881, each hereby incorporated by reference herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 schematically depicts an exemplary patterning device inwhich a plurality of individually controllable colorant applicators,arranged along the length of a series of color bars, are deployed acrossthe path of a substrate web to be patterned.

[0034]FIG. 2 schematically depicts a plan view of the device of FIG. 1,showing patterned areas of the substrate, intended to be uniformlycolored, that carry several patterning artifacts caused by individualcolorant applicator malfunctions.

[0035]FIGS. 3A through 3D depict patterned areas of a substrate at anindividual pixel scale. FIG. 3A depicts a fill area of an originalpattern, showing the confinement of light and dark pixels to variouscolumns within the pattern. FIG. 3B depicts the results of applying theteachings herein to construct an Multi-pixel Offset Unit (“M.O.U.”) tobe used in forming an appropriate superpixel in which each column of thepattern contains all four of the individual pixel colors, in accordancewith one embodiment of the teachings herein. FIG. 3C. depicts theresulting superpixel, suitable for tiling within a fill area of thepattern. FIG. 3D depicts the superpixel as tiled within a fill area.

[0036]FIG. 4 depicts a four-by-four pixel array (i.e., a superpixel)that indicates the placement of different colorants within the array inaccordance with the teachings herein.

[0037]FIG. 5 depicts a six-by-six pixel array (i.e., a superpixel) thatindicates the placement of different colorants within the array inaccordance with the teachings herein.

[0038]FIG. 6A depicts an eight-by-eight pixel array (i.e., a superpixel)that indicates the placement of different colorants within the array inaccordance with the teachings herein.

[0039]FIG. 6B depicts an alternative eight-by-eight pixel array (i.e., asuperpixel) that indicates the placement of different colorants withinthe array in accordance with the teachings herein.

[0040]FIG. 7 depicts a ten-by-ten pixel array (i.e., a superpixel) thatindicates the placement of different colorants within the array inaccordance with the teachings herein.

[0041]FIG. 8 depicts a twelve-by-twelve pixel array (i.e., a superpixel)that indicates the placement of different colorants within the array inaccordance with the teachings herein.

[0042]FIG. 9 depicts a textile substrate such as a carpet, having a flatsurface which has been patterned in accordance with the teachingsherein.

[0043]FIG. 10 depicts a textile substrate, such as a carpet or carpettile, having a contoured or uneven surface which has been patterned inaccordance with the teachings herein.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0044] The superpixel constructions described herein can be used inconjunction with a variety of patterning devices and substrates, so longas the patterning device is capable of applying colorants to thesubstrate on a pixel-by-pixel basis in accordance with pre-definedpatterning data. FIG. 1 shows an exemplary jet dyeing apparatus 10, suchas a Millitron® textile patterning machine developed by Milliken &Company of Spartanburg, S.C., comprised of a set of eight individualcolor bars 15, with each color bar capable of dispensing dye of a givencolor, positioned in fixed relationship within frame 20. A greater orfewer number of color bars may be used, depending upon the desiredcomplexity of the apparatus, the need for a wide range of colors, andother factors.

[0045] Each color bar 15 is comprised of a plurality of individuallycontrollable dye applicators arranged in spaced alignment along thelength of the color bar and supplied with the colorant assigned to thatcolor bar. The number of applicators per unit length of the color barmay be, for example, ten to the inch, twenty to the inch, or some othernumber. Each color bar extends across the full width of substrate 25. Asdepicted, unpatterned substrate 25, such as a textile fabric, may besupplied from roll 30 and is transported through frame 20 and under eachcolor bar 15 by conveyor 40, which is driven by a motor indicatedgenerally at 44. After being transported under color bars 15 in a mannerthat provides for the accurate pixel-wise placement of colorant inprecisely-defined areas of the substrate, now-patterned substrate 25Amay be passed through other dyeing-related coloring steps such asdrying, fixing, etc. With appropriate modification of the transportmechanism, the substrate to be patterned may also be in the form ofdiscrete units (e.g., individual carpet tiles, mats, or the like).

[0046]FIG. 2 is a schematic plan view of the patterning device ofFIG. 1. Included in this view are block representations of computersystem 50′ associated with electronic control system 55, electronicregistration system 60, and rotary pulse generator or similar transducer65. The collective operation of these systems results in the generationof individual “on/off” actuation, commands that result in the accuratepixel-wise application, on the surface of moving substrate 25, of thecolorants necessary to reproduce the desired pattern using thepattern-specified colors, as described in more detail incommonly-assigned U.S. Pat. Nos. 4,033,154, 4,545,086, 4,984,169, and5,208,592, each of which is hereby incorporated by reference herein.

[0047] In the operation of patterning devices such as that depicted inFIGS. 1 and 2, occasionally one or more of the hundreds or thousands ofindividual dye applicators, each of which may comprise preciselydesigned, individually-actuatable electro-mechanical valve mechanismsand fluid passageways, may fail to deliver the appropriate volume ofliquid colorant to the specified area on substrate 25. Typically, thissituation may be due to a misalignment, mis-adjustment or a blockage orother malfunction of the applicator(s). If the problem is transient innature, the resulting pattern irregularity may be quite localized on thesubstrate and may not be visually obtrusive (depending upon the natureof the pattern, the selected colors, and other factors). If, however,the problem is persistent or frequently recurring, the resulting patternirregularity may manifest as a noticeable line, streak, or band thatextends for some distance in the machine direction, as shown at 84, 86,and 88 in FIG. 2. In either case, the resulting patterned substrate mustbe considered irregular, and the carpet or other article being patternedmay be deemed off-specification and unmarketable as first quality if theirregularity is sufficiently severe. It is also possible that individualapplicator characteristics, although within the envelope associated with“normal” applicator performance, may, be sufficiently diverse as togenerate visually noticeable non-uniformities in “solid” or nominallyhomogeneous areas of the substrate pattern.

[0048] Irregularities of this type, while always undesirable, areparticularly visually obtrusive in pattern areas which are intended tocarry a uniform solid color, as depicted by areas 70 and 80 in FIG. 2,because it is in these areas that the resulting bands, streaks, and (inthe case of momentary or intermittent malfunctions) non-periodicspeckles or other pattern irregularities typically are the most visuallyprominent.

[0049] It has been unexpectedly discovered that an effective way tominimize the prominence of such patterning artifacts is to develop acarefully constructed superpixel, comprised of individual pixels of thesame or different colors, for use as a repeating unit. By so doing, thevisual impact of one or more improperly functioning applicators can beso effectively disguised so as to make the resulting patternirregularity nearly invisible. There are several techniques that may beused to construct such superpixel, each of which shall be describedbelow.

[0050] One preferred approach is depicted in FIGS. 3A through 3D. FIG.3A depicts a close-up view of a fill area in a pattern, showing theregular arrangement of pixels, each carrying one of the four differentcolors that collectively, in the pixel color ratios indicated, arenecessary to form the target color for that fill area. As is shown inFIG. 3A, the pixels assigned lighter colors and the pixels assigneddarker colors are arranged in separate columns (for example, columns 110and 115, respectively). If the colorant applicator(s) responsible forthe application of the respective colorants to columns 110 and 115functions improperly, and the pixels in one such column are not coloredas intended, the resulting pattern irregularity may quickly evolve intoa visible pattern artifact due to the straight line nature of theirregularity, as well as the well-known propensity of the human eye todiscern such straight line “patterns” when viewed against themore-or-less uniformly colored background of the fill area.

[0051]FIG. 3B depicts an approach for adjusting the distribution of thepixels comprising the fill area color in a way that minimizes the visualimpact of an improper functioning colorant applicator under thesecircumstances. This approach begins with the construction of aMulti-pixel Offset Unit or M.O.U., as identified at 120 in FIG. 3B. Thisis simply a pixel array of the minimum size necessary to contain pixelshaving the proper colors—in relative numbers reflecting the proper colorratios—necessary to reproduce the target color in the fill area on thesubstrate. This may involve having some pixels with the same color (asindicated in FIG. 3B) or may involve a set of pixels in which each pixelhas been assigned a color that is unique within the M.O.U.

[0052] Where multiple pixels having the same color are used, it ispreferred that those pixels not be placed in side-wise adjacent relation(i.e, same-color pixels should be separated, or, at a minimum, shareonly a common corner, rather than a common side). For example, if thedesired color is a green, and the process colorants available includeonly blue and yellow, then the design of the M.O.U. should avoid, to theextent possible, the occurrence of blue or yellow pixels in side-by-siderelationship. The visual effect of having groups of pixels assigned thesame color is somewhat mitigated by the quantity of colorant used, thedegree to which the colorant may be absorbed or diffused by thesubstrate surface, and other factors.

[0053] In the example depicted in FIG. 3A, it will be noted that theoriginal design shows rather prominent vertical banding due to thealignment of pixels of similar colors in the vertical direction (i.e.,colors are restricted to specific columns). In order to reach the goalof having all colors appear in each row, the M.O.U. depicted in FIG. 3Bis constructed, comprised of a single row eight columns in width. Withconsideration given to the specific arrangement of pixels within theM.O.U., the M.O.U. is then shifted one row down and three columns to theright, forming a “Z”-shaped superpixel 125 (the shape of which shall bereferred to an offset rectangular superpixel) indicated in FIG. 3C. Thisspecific offset yields a superpixel that, when tiled, creates columns ofpixels within the tiled areas in which, for every column, all pixelcolors are represented. Additionally, it will be observed that pixels ofthe same color are always separated (in a side-wise adjacent sense) byat least one pixel of a different color, although some pixels of thesame color are adjacent in a corner-to-corner sense.

[0054] In this way, when the superpixel 125 is tiled across a fill areaof the substrate as indicated in FIG. 3D, that fill area will beperceived as having the desired color (i.e., the target color), and thevarious constituent colors contributed by individual pixels will bearranged in a way (i.e., in columns extending in the machine direction)that can effectively mask the improper functioning of one or morecolorant applicators by preventing the formation of continuous streaksor bands (caused by a series of contiguous, improperly colored pixelsextending in the machine direction) on the substrate.

[0055] The array comprising the Multi-pixel Offset Unit can be square,but preferably, as depicted in FIG. 3B, is more laterally oriented,i.e., one having more columns than rows, where the columns are alignedwith the machine direction. This M.O.U. is then replicated and shifted,in both the column direction (i.e., in the machine direction, orvertically in the drawings) and row direction (i.e., laterally withrespect to the machine direction, or horizontally in the drawings), forthe purpose of assuring that pixels of every assigned color willeventually appear in each and every column. The number of columns androws in the M.O.U. depends upon the number of different pixel colorassignments necessary to create the desired target color, as well asother factors. Although the M.O.U. shown in FIG. 3B happens to be a 1×8array, M.O.U.s (and corresponding superpixels constructed from suchM.O.U.s) are by no means restricted to single rows or to a minimum ormaximum of eight columns. Indeed, it is contemplated that M.O.U.s andcorresponding superpixels having a greater or lesser number of pixels,in rectangular, offset rectangular, square, or other geometricconfiguration that accommodates the tiling of the superpixel.

[0056] M.O.U.s and corresponding superpixels of this kind may begenerated manually, or perhaps with the assistance of a ditheringalgorithm, using software such as Adobe PhotoShop® published by AdobeSystems Incorporated, San Jose, Calif., or other suitable designsoftware. In such software, the original pattern is analyzed, oh apixel-by-pixel basis, and an M.O.U.—preferably, but not necessarily, inthe form of a rectangular array—comprising all colors necessary tocreate the target color is identified. As indicated in FIG. 3C, ageometric translation or offset is then performed to arrive at asuperpixel that, when tiled, has, in each column (perhaps as extendedover multiple adjacent superpixels), pixels representing each of thedifferent colors from the original M.O.U.

[0057] While this approach is relatively simple to implement, and willeffectively reduce the visual impact of banding and streaking due tocolorant applicator malfunctions, it may be less effective at reducingthe occurrence of certain pattern artifacts that result from thegeometric alignment of individual elements within the pattern, as thoseelements are tiled throughout an area of the substrate. For illustrativepurposes only, it may be seen that the variously colored pixels depictedin FIG. 3A can generate a pattern artifact in the form of distinct“lines” 130 in a diagonal direction (sometimes referred to as twilllines) within the pattern area. In many cases, these twill lines aredesirable, or, if not, the combination of substrate absorbency, colorantquantity, and other factors is sufficient to diffuse and mask suchareas, thereby preventing the formation of visually obtrusive twilllines. However, in some cases, such twill lines can become visuallyobjectionable where, for example, the pattern is viewed at a relativelylow sight angle, as may occur if the pattern extends across a relativelylarge expanse of substrate (e.g., the carpeting of a large room).

[0058] In those situations in which the use of M.O.U.s in accordancewith the teachings above results in the formation of twill lines thatcause visually objectionable pattern artifacts, an alternativeembodiment for the arrangement of pixels within a superpixel may beused. Through use of this alternative embodiment, as described below,the resulting superpixel (1) will be relatively resistant to theformation of patterning irregularities due to the malfunction of one ormore colorant applicators, as discussed herein, and (2) will berelatively resistant to the formation of patterning artifacts such astwill lines.

[0059] It has been unexpectedly determined that adaptation of some ofthe techniques used in the art of constructing sateen weaving patternscan be advantageously adapted to the generation of superpixels, toachieve the same goals as the technique described above, i.e.,distributing pixels within a superpixel in a manner that reduces theapparent alignment of pixels of the same or similar color, so thatapplicator malfunctions do not generate bands and streaks that appear sovisually prominent as to render the pattern visually objectionable. Inparticular, the techniques and patterns used to generate irregularsateen weaves have been found to be particularly well suited to thegeneration of superpixels that do not give rise to visually prominentpattern artifacts, including unintended twill lines. The details ofthese novel adaptations are given below.

[0060]FIG. 4 depicts a 4×4 array 140, representing 16 individual pixels,each representing one of four different colors, arranged within a 4×4superpixel. The relative numbers of the respectively colored pixels isdetermined by the desired target color within the fill area of thepattern, and may be adjusted as necessary. The arrangement of theindividually-colored pixels within the superpixel, however, ispreferably in accordance with the arrangement set forth in FIG. 4. Thisarrangement, derived from and analogous to irregular sateen patternsfound in the weaving art, involves the strategic placement of colors ina way that minimizes or prevents the occurrence of same color more thanonce in any given row or column, and minimizes the occurrence ofpatterning artifacts such as twill lines generated by the diagonalalignment of pixels of substantially the same color. At the same time,this arrangement achieves its primary objective, that of a superpixelconstruction that is resistant to patterning irregularities due to themalfunction of one or more colorant applicators, a consideration totallyinapplicable to the weaving art.

[0061] There are various ways in which the actual selection of color tobe assigned to each of the 16 pixels can be made. For example, one canuse a dithering algorithm to develop a spectrum of colors that, whenproperly arranged, will mimic the desired target color. Becausedithering algorithms usually define both the proportion and thearrangement of variously colored pixels on the substrate, using theteachings herein in combination with dithering techniques must be donewith care to avoid compromising the chromatic or visual effectiveness ofthe resulting dithered pattern. Accordingly, in many cases it will bepreferred to use the teachings herein in conjunction with moretraditional methods of superpixel generation, i.e., using the skills ofa designer to construct, on a pixel-by-pixel basis, a superpixel havingthe desired composition of variously colored pixels, distributed inaccordance with the teachings herein, to be used in coloring a givenfill area within an overall pattern.

[0062] Although a superpixel based upon the 4×4 array discussed abovemay be quite effective in emulating the desired target color, it imposesa moderate limitation on the designer in terms of the number of pixelsavailable to (1) generate the desired perceived color, through ditheringor other means, and (2) distribute the variously colored pixels withinthe superpixel in a way that minimizes both heather and the appearanceof twill lines. It has therefore been found preferable in many cases touse a somewhat larger array, thereby increasing the flexibility ofindividual pixel placement and the range of perceived color that can berepresented by the superpixel. If a primary objective of minimizing theinadvertent generation of visually prominent twill lines is to be met,the construction of larger N×N arrays should limit N to even integers;arrays of odd order (e.g., where N is an odd integer) tend to arrangesimilarly colored pixels in ways that form diagonal twill lines,analogous to the teachings associated with the theory of “regular”sateen weaving constructions.

[0063]FIG. 5 depicts a 6×6 array 150, representing 36 individual pixelswithin a 6×6 superpixel. As shown in FIG. 5, it has been assumed that atotal of six different colors will be needed to reproduce the desiredtarget color. As before, different proportions of the various colors maybe used, as necessary. It should be noted that, once the placement ofthe first color within the superpixel is complete, the placement of theremaining five colors can be derived simply from choosing a procedure(e.g., consistently placing each successive color in the pixel havingsame relative position with respect to the preceding pixel, as explainedbelow) that will place those remaining colors in the same positionrelative to the first color. By so doing, the placement of the remainingcolors can be presumed to be placed in a way that will minimize orprevent the occurrence of pattern artifacts, and will also serve theoverall objective of creating a superpixel that is resistant to colorantapplicator malfunctions.

[0064] Accordingly, the superpixel depicted in FIG. 5 has beenconstructed by assignment of the first color in accordance with sateenweaving practice. For purposes of discussion, such pixels may bereferred to as “base” pixels, as these pixels form the reference pointsfrom which the color assignment of all other pixels within thesuperpixel are determined. The second color is assigned to the pixeldirectly above the first color pixel in each of the columns. The thirdcolor is assigned to the pixel directly above the second color pixel ineach of the columns, and so forth, with appropriate wrapping, i.e., withthe assignment reverting to the bottom of each column when the upperportion of the column is filled. Alternatively, the procedure could havecalled for assignment of the second color to the pixel to the immediateright of the first color, assignment of the third color to the immediateright of the second color pixel, and so forth, with appropriate wrappingin each case.

[0065] By extension, corresponding assignments to the left, or below, orsome other consistent relative placement using the pixel assigned to theimmediately preceding color as the “base” or reference pixel, is alsocontemplated. The objective of these various placement algorithms is thesame: by consistently following the same rule for all colors in thesuperpixel, the individual pixels of a given color will be distributedthroughout the area tiled by the superpixel in the same way as thepixels of all other colors contained in the superpixel (i.e., whenaccommodations are made for lapping, all pixels of any given color formthe same pattern within the area tiled by the superpixel).

[0066] This approach can be adapted to superpixels constructed fromlarger arrays, as well. FIGS. 6A and 6B depict alternative 8×8superpixels 160A and 160B, again with placement of the base pixelscarrying the first color being in accordance with sateen weavingpractice and using the “adjacent and above” process to establish theposition of the remaining seven colors. FIGS. 7 and 8 show respectivelylarger superpixel constructions for use, for example, where a largernumber of individually colored pixels must be used as dither elements togenerate the desired overall color from the available set of processcolors.

[0067] Depending upon the choice of colors, it has been found that,while all such procedures might be equally effective at minimizing thegeneration of twill lines, not all are equally effective at distributingvarious colors throughout the superpixel in a way that maximizes therelative uniformity or homogeneity of the color throughout the pixel.For example, if a dithering algorithm specified a given proportion ofindividual blue and green pixels within a superpixel in order to achievea desired overall color, it would be undesirable to consolidate all theblue and green pixels and place them on opposite sides of thesuperpixel, rather than intersperse them throughout the superpixel (tothe extent consistent with the dithering algorithm and the resultingoverall visual effect presented by the dithered area).

[0068] The preceding discussion has been primarily directed to thedistribution of colors within a superpixel. The discussion that followsis directed primarily to the selection of the colors to be distributed,with the objective of emulating, as closely as possible given theselection of available process colorants and available blending anddithering techniques, the target color in fill areas of the substrate.

[0069] If the number of process colors needed to generate a givenpattern is relatively small and a specific fill color area within thatpattern is particularly large or otherwise prominent (or, for example,if the “pattern” consists of a single uniform solid color that is aprocess color or a simple in situ blend of a relatively few processcolors), it is contemplated that the patterning device can be operatedwith several of the color bars dispensing the same colorant, but withuse of the techniques disclosed herein for distributing such colorant onthe substrate surface. If, for example, the substrate is to be dyed auniform shade of red, and that color corresponds to an available processcolorant, then several of the color bars (e.g., bars 1 through 4, orbars 2, 4, 6, and 8) of the patterning device of FIGS. 1 and 2 can beloaded with that same red process colorant. The manner in which thiscolorant is applied to the substrate, however, is governed by theteachings herein—a superpixel is constructed in which the colorants fromcolor bars 1 through 4 are regarded as separate and distinct forpurposes of assigning colorant to individual pixels within the area ofthe substrate to be colored, and that superpixel (e.g., one constructedalong the lines of FIG. 3C or FIG. 4) is tiled across the surface of thesubstrate. The overriding principle is similar: relying upon differentcolorant applicators to provide the same colorant to different side-wiseadjacent pixels extending in the machine direction.

[0070] By so doing, the contribution of the colorant applicators on anyindividual color bar 1 through 4 is dispersed throughout the superpixeland thereby effectively dispersed throughout the pattern area in amanner that encourages an artifact-free, uniformly colored solid shadearea that is free of visually obtrusive bands and streaks due toapplicator malfunctions (or perhaps due merely to within-specificationmechanical differences among various colorant applicators). It should benoted that, where an artifact-free, uniformly-colored solid shade isdesired, it may be unnecessary to use a superpixel containing 16 or morepixels (as depicted in FIG. 3C and FIGS. 4 through 8), particularly ifthe target color is expressed by a process colorant or can be easilyderived (e.g., via in situ blending) from a relatively few processcolorants. In that case, it is contemplated that smaller superpixels,perhaps containing as few as four pixels, may be used, either in asquare array, an offset rectangular array, or some other readilytile-able configuration. Specifically contemplated in such circumstancesare superpixels in the form of N×M pixel arrays, where N and M can beequal or different, and the total number of pixels can be 4, 6, 8, 9,10, 12, or 14.

[0071] At the other extreme, where the desired pattern requires colorsthat do not easily correspond to the process colors in use, but rathermust be derived from a given set of process colors, several techniquesmay be used. For example, two or more colorants may be applied to thesame pixel area, thereby forming an in situ blend of the two processcolors. By adjusting the order and the relative proportion of thedelivered colorants, an individual pixel can be made to carry any one ofa spectrum of colors not directly represented by any single processcolor, but rather represented by various combinations of the processcolors (i.e., various combinations of process colorants). A secondexample involves dithering, a well-known graphic arts technique in whicha pixel of a given, unavailable color (i.e., not a process color or anachievable blend of process colors) may be approximated by thesubstitution of a small group of pixels that are colored with processcolors or achievable blends of process colors (collectively, such colorsare said to make up the “dither palette”) in a way that, at a distance,gives the appearance of the desired color.

[0072] There are many software algorithms available to accomplishdithering, such as those found in Adobe Photoshop®, Adobe Illustrator®,Corel Draw®, etc. or those based upon the work of Thiadmer Riemersma, asdescribed in “A Balanced Dithering Technique,” appearing in theDecember, 1998 issue of C/C++ User's Journal, or, often preferably,those based upon Floyd-Steinberg dithering and described, for example,in the article appearing at Page 253 of the Mar. 28, 1995 issue of in“PC Magazine.” The image to be dithered is analyzed and re-constructedusing only pixels having colors found in a predetermined ditheringpalette, using the conventional dithering techniques found in thecommercially available software discussed above, or other appropriatedithering software.

[0073] The colors that comprise the dithering palette may be thosecolors comprising the “primary” or process colors available fordispensing by the patterning system to be used, for example, the colorsassociated with each of the eight color bars 15 of FIGS. 1 and 2. If theprinting system allows for the in situ blending of colors, in whichdifferent colors may be generated by the mixing or migration ofcolorants after the colorants have been applied to the substrate, thedithering palette may be augmented by the addition of variouscombinations of process colors, as applied to the same or adjacentpixels, thereby forming in situ mixtures or blends of process colors onthe substrate surface. This will provide a dithering palette having manymore colors that the number of available process colors. In a preferredembodiment, the colors of the dithering palette are comprised of (1)colors of the available liquid colorants to be used in the printingprocess, (2) pre-selected proportional blends of those colors, as thosecolors would appear if applied in sequence to the same pixel and allowedto mix on the substrate, one color superimposed on the other, to achievean in situ blend of the applied colors, and (3) colors in which suchproportional blends are intended to migrate and mix across pixelboundaries in a controlled, predictable way, for example, in accordancewith the teachings of commonly-assigned U.S. patent application Ser. No.08/834,795, the teachings of which are hereby incorporated by reference.

[0074] The above-referenced U.S. patent application describes a specialcase in which a potential limitation in the colorant delivery system maybe overcome when attempting to generate mixtures of colors on asubstrate. It is known that colors that are not available as processcolors may be generated by blending specific combinations of processcolors on the substrate, i.e., two or more different colorants areapplied to the same area on the substrate and are allowed to mix,thereby forming a new color. A potential problem arises when therelative proportion of a constituent colorant is less than the deliverysystem of the patterning device can accommodate.

[0075] For example, assume that a specific shade of green is desired,and must be generated from a combination of process colorants of blueand yellow. Assume further that the specific shade of green desired isachievable only if the relative proportion of those colorants,individually applied to the same pixel-sized area of the substrate, is 2parts blue and 8 parts yellow. The valve response of the patterningdevice may be unable to deliver the blue colorant in such a smallquantity—assume, for example, that a 30% saturating quantity (based on abaseline saturating quantity of 100%, i.e., that quantity that issufficient to fully saturate, but not oversaturate, the substrate atthat location) is the smallest quantity of colorant that can be reliablydelivered to an individual pixel. In that case, it is possible to formthe desired shade of green by forming a multiple pixel structure,generally comprised of between two and sixteen or more individual,contiguous pixels that may be used within the image in the same manneras a single pixel. The number of pixels to be used depends upon a numberof factors, including the ratio of colorants forming the desired blendedcolor and the desired relative granularity or “heather” that isartistically acceptable in the pattern.

[0076] This multiple pixel structure, a specific kind of superpixelreferred to as a “metapixel,” is characterized by the formation, withinthe metapixel, of individual pixels that are relatively oversaturatedwith colorant and adjacent pixels that are relatively undersaturatedwith colorant, thereby encouraging the migration of colorant from theoversaturated areas to the undersaturated areas. As a consequence,minimum colorant delivery limitations can be overcome by calculating anddelivering a quantity of colorant that, on average, meets theproportional blending requirements of the desired color. In thisinstance, the blue and yellow colorants are applied to the group ofcontiguous pixels forming the metapixel in a way in which the averagequantity of blue colorant contained throughout the metapixel is 20% andthe average quantity of yellow colorant contained throughout themetapixel is 80%, yielding an average quantity of colorant that is 100%,i.e., that quantity of colorant that saturates, but does notoversaturate, the substrate at that location. As explained below, thiscan be achieved using several combinations or arrangements of pixels towhich various individual colorant quantities—but never less than 30% ofany single colorant have been applied.

[0077] An elementary metapixel can be imagined by thinking of fourcontiguous pixels, arranged in a square (e.g., 2×2) array, intended toreproduce a shade of green. Assume that two of these pixels, perhapsarranged along a diagonal, each contains 40% of a saturating applicationof blue colorant, as well as 80% of a saturating application of yellowcolorant. While each of these applications of colorant would beundersaturating if considered individually (because each is less than100%), the combination of colorants in each of these two pixels resultsin a 120% level of saturation (40%+80%), and therefore results in anoversatuating condition within those two pixels. Assume that into theremaining two pixels comprising the square array is placed an 80%saturating application of yellow colorant. The resulting combinationaverages to a 20%/80% proportion of blue colorant to yellow colorantwithin the four pixel array, which presumably is the appropriate rationeeded to reproduce the desired shade of green, and yields an averagesaturation level of 100%. Given the absorbent nature of the textilesubstrates to which this technique is applicable (which substrates tendto promote inter-pixel blending of colorants, and, particularly, themigration and blending of colorants from oversaturated areas intoundersaturated areas), the overall effect is that of a four pixel arrayin which the overall color is similar to that which would have beenobtained by the application of a 20% quantity of blue colorant and an80% quantity of yellow colorant to each of the four pixels comprisingthe array.

[0078] Alternatively, this same overall colorant average within themetapixel array could have been achieved by the same 40% application ofblue colorant to the same two pixels within the array, but with theremaining two pixels each receiving all of the necessary yellow colorant(i.e., an oversaturating, 160% application). Generally, because thislatter distribution of colorants must rely more heavily uponunrestricted colorant migration on the substrate, the first describedcolorant application process (i.e., creating two individual pixelshaving a 40%/80% blue/yellow colorant application and two individualpixels having an 80% yellow colorant application, and thereforeconstructing an array in which the yellow colorant is more uniformlyapplied within the array) will be preferred under most conditions. Ofcourse, metapixel arrays comprised of other configurations ofoversaturated and undersaturated pixels can be constructed—for example,3×3 arrays, or irregularly shaped arrangements of pixels—so long as (1)the average proportion of colorants within the metapixel array reflectsthe proportions of colorants desired, (2) overall average saturationlevel within the metapixel does not appreciably exceed 100% (to avoiddrying and other problems), and (3) the minimum colorant deliverylimitations of the patterning device are observed.

[0079] The techniques described above are believed to be applicable to avariety of substrates, although absorbent textile substrates arepreferred. It is contemplated that such preferred substrates maycomprise interior fabrics and substrates, such as drapery and upholsteryfabrics, table linen, and various floor coverings, as well as othertextile applications, (e.g., automotive interior fabrics and carpeting,automotive and non-automotive floor mats, etc.). It has been found thatthis technique is particularly well adapted for use in decorative floorcovering applications, including carpets, rugs, carpet tiles, mats, andthe like. The following are examples of two such applications.

EXAMPLE 1

[0080] The substrate is a high twist frieze cut pile carpet, comprisedof two-ply, high twist nylon 6,6 yarn (1180 filament, 17 dpf) woven intoa 4 oz woven polypropylene backing at 7.8 stitches per inch and having atufting gauge of {fraction (1/8)} inch that results in a total finishedpile height of about {fraction (3/4)} inch and a yarn weight of about 38oz./yd. This substrate is then patterned in accordance with theteachings herein, as follows.

[0081] The pattern desired is merely a relatively uniform color, withthe intentional introduction of heather for visual interest. Theoriginal pixel-wise components of the desired color are indicated inFIG. 3A. However, because of the concentration of certain colors withincertain columns, it is recognized that this pattern is vulnerable tostreaking and banding. Accordingly, the same pixels, in the sameproportion, are rearranged to form an M.O.U., as indicated in FIG. 3B.The M.O.U. is then configured to form a superpixel that (1) representsthe desired color (due to the selection of the colors of the individualconstituent pixels) and (2) forms a replicatable unit that can be tiledacross the substrate, as shown in FIGS. 3C and 3D. The proper colorapplicator actuation instructions are generated, and the carpet ispatterned using the device of FIGS. 1 and 2. The result is a carpethaving a pattern in which fill areas have an exceptionally uniformappearance and, at a modest viewing distance, give the appearance of asolid color, as depicted in FIG. 9.

EXAMPLE 2

[0082] The substrate is a loop pile carpet tile, comprised of three-ply,space dyed and heat set nylon 6.6 yarn tufted in {fraction (1/8)} inchgauge resulting in a finished pile height of 0.125 inch and a yarnweight of 20 oz/yd. The carpet backing is PVC-Free Comfort Plus Cushion.To give additional visual interest, the pile is sculpted somewhat,yielding a slightly undulating surface. This substrate is then patternedin accordance with the teachings herein, as follows.

[0083] The pattern desired is comprised of pre space dyed yarn that isthen overdyed completely with areas of contrasting color, similar to thedesign shown in FIG. 10. The pixel-wise components of the desired colorfor the fill areas are determined by a designer using design software,and are determined to require six process colors. The, arrangement ofthose colors, on an individual pixel basis, is accomplished inaccordance with the teachings herein, as indicated in FIG. 6A. Theresulting superpixel (1) represents the desired color (due to theselection of the colors of the individual constituent pixels) and (2)forms a replicatable unit that can be tiled across the substrate, asshown in FIG. 6A. The proper color applicator actuation instructions aregenerated, and the carpet is patterned using the device of FIGS. 1 and2. The result is a carpet having a pattern in which fill areas have anexceptionally uniform appearance and, at a modest viewing distance, givethe appearance of a solid color, as depicted in FIG. 10.

[0084] The substrate is a loop pile carpet tile, comprised of two-ply,high twist nylon 6,6 yarn (1180 filament, 17 dpf) woven into a 4 oz.woven polypropylene backing at 7.8 stitches per inch and having atufting gauge of {fraction (1/10)} inch that results in a total finishedpile height of about {fraction (3/4)} inch and a yarn weight of about 18oz./yd. To give additional visual interest, the pile is sculptedsomewhat, yielding a slightly undulating surface. This substrate is thenpatterned in accordance with the teachings herein, as follows.

[0085] The pattern desired is comprised of a colored background withlarge fill areas of a contrasting color, similar to the design shown inFIG. 10. The pixel-wise components of the desired color for the fillareas are determined by a designer using design software, and aredetermined to require six process colors. The arrangement of thosecolors, on an individual pixel basis, is accomplished in accordance withthe teachings herein, as indicated in FIG. 6A. The resulting superpixel(1) represents the desired color (due to the selection of the colors ofthe individual constituent pixels) and (2) forms a replicatable unitthat can be tiled across the substrate, as shown in FIG. 6A. The propercolor applicator actuation instructions are generated, and the carpet ispatterned using the device of FIGS. 1 and 2. The result is a carpethaving a pattern in which fill areas have an exceptionally uniformappearance and, at a modest viewing distance, give the appearance of asolid color, as depicted in FIG. 10.

[0086] It should be understood that the specifics of the construction ofthe textile substrates in the above examples are not critical. Thepatterning techniques disclosed herein are applicable to a variety ofabsorbent textile substrates, including, but not limited to, carpets,carpet tiles, rugs, and mats having the widest variety of constructions,so long as each has sufficient dimensional stability for acceptabletransport and pattern transfer and the face yarns are capable ofaccepting dye in an acceptable manner.

[0087] While the invention has been described in connection with theembodiments discussed above, it is not intended to limit the scope ofthe invention to the particular form set forth, but on the contrary, itis intended to cover such alternatives, modifications, and equivalentsas may be included within the spirit and scope of the invention asdefined by the appended claims.

1. A product of the process of assigning liquid colorants to individualpixels within a superpixel, said pixels being arranged within saidsuperpixel in an array comprised of columns and rows, wherein each ofsaid pixels is assigned at least one process color resulting in theapplication of at least one liquid colorant to an area on said substratesurface corresponding to said pixel, and wherein said superpixel, whenappropriately tiled across a pattern area on an absorbent textilesubstrate, effectively simulates the appearance of a desired fill colorwithin said pattern area, said method comprising the steps of: a.defining an array comprised of rows and columns of individuallycolorable pixels, each row and column containing at least two pixels; b.assigning a color to each of said individual pixels comprising saiddefined array, said assigned pixel colors collectively forming a desiredfill color within said array when said array is observed from a distanceat which said individually assigned pixel colors are visuallyindiscernible, and wherein all side-wise adjacent pixels along any rowof said array will be assigned different colors; c. configuring aplurality of said arrays in adjacent relation to form a superpixelcapable of being tiled across said substrate surface to form said fillcolor, said superpixel being configured so that, when tiled within apattern area on said substrate surface, every assigned pixel colorwithin said superpixel appears in every column defined by said tiledsuperpixels within said pattern area. 2-7. (canceled)
 8. The product ofthe process of claim 1 wherein said textile substrate is a textile floorcovering comprised of fibers selected from the group consisting ofpolyamide fibers and wool fibers. 9-10. (canceled)
 11. The product ofthe process of claim 1 wherein said color assigned to said pixel isgenerated by the in situ blending of at least two liquid colorantsapplied to the same pixel on said substrate surface. 12-13. (canceled)14. The product of the process of claim 1 wherein said color assigned tosaid pixel is generated by the in situ blending of liquid colorantsapplied to a first and a second, adjacent pixel within said superpixel,and wherein the volume of liquid colorant applied to said first pixel issufficient to oversaturate said first pixel and the volume of liquidcolorant applied to said second pixel is insufficient to saturate fullysaid second pixel. 15-17. (canceled)
 18. The product of the process forconstructing a superpixel to be replicated on the surface of anabsorbent textile substrate, said superpixel being comprised of aplurality of contiguous pixels that collectively provide said superpixelwith a geometric shape that can be tiled on said substrate surface, eachof said plurality of contiguous pixels comprising said superpixel beingassigned a color from a dither palette in a relative proportion tosimulate a target color, wherein said colors are individually assignedto pixels within said superpixel in accordance with a placementalgorithm that precludes the assignment of the same color on adjacentpixels within said superpixel, said individual assignment of color toeach of said plurality of contiguous pixels results in the applicationof at least one liquid colorant to an area on said substratecorresponding to that pixel by a plurality of individually-actuatedcolorant applicators in response to digitally-encoded patterning date.19-23. (canceled)
 24. The product of the process of claim 18, whereinsaid substrate is a textile color covering comprised of fibers selectedfrom the group consisting of polyamide fibers and wool fibers. 25.(canceled)
 26. The product of the process of claim 18, wherein saidcolor assigned to said pixel is generated by the in situ blending of atleast two liquid colorants applied to the same pixel on said substratesurface. 27-28. (canceled)
 29. The product of the process of claim 18wherein said color assigned to said pixel is generated by the in situblending of liquid colorants applied to a first and a second, adjacentpixel on said substrate surface, and wherein the volume of liquidcolorant applied to said first pixel is sufficient to oversaturate saidfirst pixel and the volume of liquid colorant applied to said secondpixel is insufficient to saturate fully said second pixel. 30-33.(canceled)
 34. The product of the process of claim 18 wherein theapplication of said algorithm results in the placement of color in rowsand columns within said superpixel such that each row and each columncomprising said superpixel has no more than one pixel of a given color.35. The product of the process for constructing a superpixel to bereplicated on the surface of an absorbent textile substrate, saidsuperpixel being comprised of an N×N array of pixels, each of saidpixels having been assigned a color from a dither palette in a relativeproportion to simulate a target color, wherein said colors are assignedto individual pixels within said superpixel in accordance with aplacement algorithm that assigns a given color to a pixel in each of theN rows and each of the N columns in a manner that said given color isfound no more than once in any row or column in said array and eachpixel assigned to said given color is surrounded by pixels to whichother colors have been assigned, said assignment of color to individualpixels resulting in the application of at least one liquid colorant toan area on said substrate corresponding to that pixel 36-40. (canceled)41. The product of the process of claim 35 wherein said textilesubstrate is a textile floor covering comprised of fibers selected fromthe group consisting of polyamide fibers and wool fibers.
 42. Theproduct of the process of claim 35 wherein said color assigned to saidpixel is generated by the in situ blending of at least two liquidcolorants applied to the same pixel on said substrate surface. 43-44.(canceled)
 45. The product of the process of claim 35 wherein said colorassigned to said pixel is generated by the in situ blending of liquidcolorants applied to a first and a second, adjacent pixel within saidsuperpixel, and wherein the volume of liquid colorant applied to saidfirst pixel is sufficient to oversaturate said first pixel and thevolume of liquid colorant applied to said second pixel is insufficientto saturate said second pixel.
 46. (canceled)
 47. The product of theprocess of claim 35 wherein N is at least 4 and said placement algorithmassigns a given color to a pixel in each of the N rows and each of the Ncolumns in a manner that said given color is found no more than twice inany row or column in said array, and wherein each pixel assigned to saidgiven color is side-wise adjacent to a pixel assigned a color differentfrom said given color.
 48. (canceled)
 49. The product of the process ofclaim 35 wherein N is at least 6 and said placement algorithm assigns agiven color to a pixel in each of the N rows and each of the N columnsin a manner that said given color is found no more than twice in any rowor column in said array, and wherein each pixel assigned to said givencolor is surrounded by pixels to which other colors have been assigned.50-53. (canceled)
 54. A textile substrate comprised of fibers selectedfrom the group consisting of polyamide fibers and wool fibers, saidsubstrate having a pattern imparted by the pixel-wise application tosaid substrate, in response to electronically-defined instructions, of afirst liquid colorant representing a first color and a second liquidcolorant representing a second color, said pattern being formed, atleast in part, by a plurality of superpixels arranged in a tiledformation in which each individual superpixel is comprised of an arrayof individually colored pixels arranged in rows and columns, whereinpixels of each of said first and second colors within said superpixelare represented in each column comprising said array.
 55. The product ofclaim 54 wherein said pattern is imparted by the application of said twodifferent liquid colorants to the same pixel, thereby generating an insitu blend of said liquid colorants.
 56. The product of claim 54 whereinsaid pattern is imparted by the application of a first liquid colorantto a first pixel, and a second liquid colorant to a second pixel, wheresaid first pixel and said second pixel are adjacent, thereby generatingan in situ blend of said liquid colorants.
 57. The product of claim 56wherein said pattern is imparted by the application of said first liquidcolorant to a first pixel, and said second liquid colorant to a secondpixel, where said first pixel and said second pixel are adjacent,thereby generating an in situ blend of said liquid colorants, andwherein the volume of said first liquid colorant applied to said firstpixel is sufficient to oversaturate said first pixel and the volume ofsaid second liquid colorant applied to said second pixel is insufficientto saturate said second pixel.
 58. The product of claim 54 wherein saidsubstrate is a frieze cut pile substrate.
 59. The product of claim 54wherein said substrate is a loop carpet tile.
 60. The product of claim57 wherein said substrate is a frieze cut pile substrate.
 61. Theproduct of claim 57 wherein said substrate is a loop carpet tile.